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Long and short

jsca

Member
Hello all. Could I use both l

Hello all. Could I use both long and short shaft 40hp Mariners on my boat? Difference in prop heoght is 100 mm. Tks for reply. JJ
 
"What is the transom height of

"What is the transom height of your boat?

If you use a long shaft motor on a short transom you have about 5 inches (12.5 cm) of "leg" etc hanging below the bottom of the boat. Besides causing extra drag, you run the danger of smashing the lower unit in shallow water.

If you use a short shaft on a long transom, you run the risk of the motor sucking air, over heating and welding itself into a 200 pound lump of scrap aluminum..."
 
With a short shaft on a long s

With a short shaft on a long shaft transom add ventilation causing loss of drive and the last bit of what Graham said over heating!!!
 
"On short/long shaft, followin

"On short/long shaft, following: Standard transom = 600mm: Motor-1= 400mm: motor-2=500mm: "long-shaft motor" centre of prop is 100mm below transom: Short-shaft is level with transom. OEFFF Hope you boffins can use the slide-rule!! Tks. JJ.(S. Africa)"
 
Ok a short shaft transom heigh

Ok a short shaft transom height is 15 inches and a long shaft transom height is 20 inches.

The cavitation plate should be level or about 3/8 of an inch below the hull on a standard set up.
 
"If the center of the prop is

"If the center of the prop is level with the bottom of your boat when you have a short shaft mounted, then you have a 20" inch transom and need a long shaft motor.

The entire prop should be below the bottom of the transom..."
 
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